For an object placed at a distance 2.4 m from a lens, a sharp focused image is observed on a screen placed at a distance 12 cm form the lens. A glass…

For an object placed at a distance $\displaystyle 2.4$ m from a lens, a sharp focused image is observed on a screen placed at a distance $\displaystyle 12$ cm form the lens. A glass plate of refractive index $\displaystyle 1.5$ and thickness $\displaystyle 1$ cm is introduced between lens and screen such that the glass plate plane faces parallel to the screen. By what distance should the object be shifted so that a sharp focused image is observed again on the screeen ?